Refactoring of reading and writing of the UFS/FFS superblock.

Specifically reading is done if ffs_sbget() and writing is done
in ffs_sbput(). These functions are exported to libufs via the
sbget() and sbput() functions which then used in the various
filesystem utilities. This work is in preparation for adding
subperblock check hashes.

No functional change intended.

Reviewed by: kib

1 files changed, 43 insertions, 83 deletions

diff --git a/sys/geom/label/g_label_ufs.c b/sys/geom/label/g_label_ufs.c
index b53d6e45857e..43c44586cb05 100644
--- a/sys/geom/label/g_label_ufs.c
+++ b/sys/geom/label/g_label_ufs.c
@@ -32,11 +32,14 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
-#include <sys/kernel.h>
 #include <sys/malloc.h>
+#include <sys/vnode.h>
 
 #include <ufs/ufs/dinode.h>
 #include <ufs/ffs/fs.h>
+#include <ufs/ufs/quota.h>
+#include <ufs/ufs/extattr.h>
+#include <ufs/ffs/ffs_extern.h>
 
 #include <geom/geom.h>
 #include <geom/label/g_label.h>
@@ -56,106 +59,63 @@ __FBSDID("$FreeBSD$");
 				< G_LABEL_UFS_MAXDIFF )
 #define	G_LABEL_UFS_MAXDIFF	0x100
 
-static const int superblocks[] = SBLOCKSEARCH;
-
+/*
+ * Try to find a superblock on the provider. If successful, then
+ * check that the size in the superblock corresponds to the size
+ * of the underlying provider. Finally, look for a volume label
+ * and create an appropriate provider based on that.
+ */
 static void
 g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int what)
 {
 	struct g_provider *pp;
-	int sb, superblock;
 	struct fs *fs;
 
 	g_topology_assert_not();
 	pp = cp->provider;
 	label[0] = '\0';
 
-	if (SBLOCKSIZE % cp->provider->sectorsize != 0)
+	if (SBLOCKSIZE % pp->sectorsize != 0 ||
+	    ffs_sbget(cp, &fs, -1, NULL, g_use_g_read_data) != 0)
 		return;
-
 	/*
-	 * Walk through the standard places that superblocks hide and look
-	 * for UFS magic. If we find magic, then check that the size in the
-	 * superblock corresponds to the size of the underlying provider.
-	 * Finally, look for a volume label and create an appropriate
-	 * provider based on that.
+	 * Check for magic. We also need to check if file system size
+	 * is almost equal to providers size, because sysinstall(8)
+	 * used to bogusly put first partition at offset 0
+	 * instead of 16, and glabel/ufs would find file system on slice
+	 * instead of partition.
+	 *
+	 * In addition, media size can be a bit bigger than file system
+	 * size. For instance, mkuzip can append bytes to align data
+	 * to large sector size (it improves compression rates).
 	 */
-	for (sb = 0; (superblock = superblocks[sb]) != -1; sb++) {
-		/*
-		 * Take care not to issue an invalid I/O request. The offset of
-		 * the superblock candidate must be multiples of the provider's
-		 * sector size, otherwise an FFS can't exist on the provider
-		 * anyway.
-		 */
-		if (superblock % cp->provider->sectorsize != 0)
-			continue;
-
-		fs = (struct fs *)g_read_data(cp, superblock, SBLOCKSIZE, NULL);
-		if (fs == NULL)
-			continue;
-		/*
-		 * Check for magic. We also need to check if file system size
-		 * is almost equal to providers size, because sysinstall(8)
-		 * used to bogusly put first partition at offset 0
-		 * instead of 16, and glabel/ufs would find file system on slice
-		 * instead of partition.
-		 *
-		 * In addition, media size can be a bit bigger than file system
-		 * size. For instance, mkuzip can append bytes to align data
-		 * to large sector size (it improves compression rates).
-		 */
-		switch (fs->fs_magic){
-		case FS_UFS1_MAGIC:
-		case FS_UFS2_MAGIC:
-			G_LABEL_DEBUG(1, "%s %s params: %jd, %d, %d, %jd\n",
-				fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2",
-				pp->name, pp->mediasize, fs->fs_fsize,
-				fs->fs_old_size, fs->fs_providersize);
-			break;
-		default:
-			break;
-		}
-
-		if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0 &&
-		    ( G_LABEL_UFS_CMP(pp, fs, fs_old_size)
-			|| G_LABEL_UFS_CMP(pp, fs, fs_providersize))) {
-		    	/* Valid UFS1. */
-		} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0 &&
-		    ( G_LABEL_UFS_CMP(pp, fs, fs_size)
-			|| G_LABEL_UFS_CMP(pp, fs, fs_providersize))) {
-		    	/* Valid UFS2. */
-		} else {
-			g_free(fs);
-			continue;
-		}
-		if (fs->fs_sblockloc != superblock || fs->fs_ncg < 1 ||
-		    fs->fs_bsize < MINBSIZE ||
-		    fs->fs_bsize < sizeof(struct fs)) {
-			g_free(fs);
-			continue;
-		}
-		G_LABEL_DEBUG(1, "%s file system detected on %s.",
-		    fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
-		switch (what) {
-		case G_LABEL_UFS_VOLUME:
-			/* Check for volume label */
-			if (fs->fs_volname[0] == '\0') {
-				g_free(fs);
-				continue;
-			}
+	if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0 &&
+	    ( G_LABEL_UFS_CMP(pp, fs, fs_old_size)
+		|| G_LABEL_UFS_CMP(pp, fs, fs_providersize))) {
+		/* Valid UFS1. */
+	} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0 &&
+	    ( G_LABEL_UFS_CMP(pp, fs, fs_size)
+		|| G_LABEL_UFS_CMP(pp, fs, fs_providersize))) {
+		/* Valid UFS2. */
+	} else {
+		g_free(fs);
+		return;
+	}
+	G_LABEL_DEBUG(1, "%s file system detected on %s.",
+	    fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
+	switch (what) {
+	case G_LABEL_UFS_VOLUME:
+		/* Check for volume label */
+		if (fs->fs_volname[0] != '\0')
 			strlcpy(label, fs->fs_volname, size);
-			break;
-		case G_LABEL_UFS_ID:
-			if (fs->fs_id[0] == 0 && fs->fs_id[1] == 0) {
-				g_free(fs);
-				continue;
-			}
+		break;
+	case G_LABEL_UFS_ID:
+		if (fs->fs_id[0] != 0 || fs->fs_id[1] != 0)
 			snprintf(label, size, "%08x%08x", fs->fs_id[0],
 			    fs->fs_id[1]);
-			break;
-		}
-		g_free(fs);
 		break;
 	}
+	g_free(fs);
 }
 
 static void